1. Field
Embodiments of the invention relate to vehicles, e.g., rail vehicles. Other embodiments relate to methods and systems for controlling rail vehicles or other vehicles.
2. Discussion of Art
Especially when various on-board systems are integrated with a vehicle braking system for conjointly operating the vehicle, the vehicle may be operated according to a “worst case” assumption of braking capability. For example, in the case of a locomotive or other rail vehicle, the rail vehicle may be operated according to the assumption that only fifty percent of mechanical braking capability (e.g., air brakes) is available and with no dynamic brake capability. Making such assumptions may result in the rail vehicle being slowed earlier than necessary, which results in a loss of average speed over a full duration of a trip/mission. Additionally, this may result in delay and loss of route capacity, considering that other vehicles also operate of the same route. Furthermore, the actual braking capability may actually be less than what is assumed, due to discrepancies between actual capabilities and assumed capabilities, brake system failures during a trip, environmental conditions, etc.
One approach currently utilized to assess braking capability of a rail vehicle is to check the air brakes prior to departure to ensure that air pressure is present. This approach, however, does not provide for a true determination of braking capability or effectiveness. This is because checking for air pressure does not convey any information about how much braking force would be applied in actually using the brakes during motoring, e.g., actual braking pads or shoes may not function properly, thus not being able to apply a full breaking force to wheels of the rail vehicle, even though a positive air pressure reading is obtained.
It may be desirable to have a vehicle control system, taking into account braking system capability, that differs from those vehicle control systems that are currently available.